This invention relates to an oil-filled or oil-immersed electrical device.
Various types of electrical devices which are filled with insulating oil are widely used in, for example, power systems. Recently, with ever increasing demand for a greater and greater supply of electrical power, such electrical devices are becoming of greater and greater capacity and more and more capable of withstanding higher voltages.
One of the factors that determine the operating efficiency of such oil-filled or oil-immersed electrical devices is the characteristics of the oil that fills the device together with other component parts thereof. At present mineral oils and diphenyl chloride are most widely used for this purpose. However, mineral oils have lower dielectric constants and strength and also are less gas-absorbent so that they cannot provide sufficient properties required for high voltage and capacity types of such electrical devices and with such mineral oils it is difficult to make the device compact in size.
On the contray, diphenyl chloride has a higher dielectric constant and strength. However, it is so toxic to the human as well as animal life that in view of environmental pollution the use of this material is undesirable.
Accordingly, the primary object of the invention is to provide such electrical devices which have high operating efficiency.
Another object of the invention is to provide oil-filled or oil-immersed electrical devices having high operating efficiency which is achieved by the use of such insulating oils having good characteristics as such oils.
Still another object of the invention is to provide oil-immersed or oil-filled electrical devices employing insulating oils which are not toxic to life.
Still another object of the invention is to improve the characteristics of oil-filled electrical devices through utilization of those insulating oils which have greater dielectric constants and strengths and are more gas-absorbent than the mineral oils hitherto employed for the same purpose.
A further object of the invention is to provide such oil-filled electrical devices as aforesaid which are compact in size.
Additional object of the invention is provide an insulating oil for use in oil-filled or oil-immersed electrical devices, which has a higher dielectric constant and strength and is more gas-absorbent than the conventional mineral oils.